The field of this invention relates to the installation of fasteners. More particularly, this invention relates to apparatus for installing fasteners when the human operator and the hole at which the fastener will be installed are remotely located from each other. While the invention may be adapted for use in virtually any environment, it can be particularly advantageous for use in nuclear reactors. In such an environment, it may be desirable to have a human operator position himself some distance from a fastener installation hole to reduce the amount or possibility of radiation exposure, or because the geometrical configuration of the structure makes it difficult or impossible for the human operator to place himself in close proximity to the fastener installation hole. In these situations, a device is needed that can grip the fastener, install the fastener at a remote location, and release from the fastener so that the tool can be removed. The same tool should also be capable of removing the fastener by a human operator positioned at the remote location.
An existing tool (2) shown in FIG. 1 has been used to install fasteners such as a bolt (3) into a remotely located hole in a nuclear reactor. This tool includes a plurality of resilient fingers (4) which grip the washer (5) installed on the bolt. A beam (6) is connected to the fingers and extends between the human operator (not shown) and the installation hole (7). This length can often exceed that found on conventional fastener installation tools such as screwdrivers, and in some applications can measure as much as twenty to thirty feet. The effective use of this tool depends on the human operators"" ability to position the tool without excess movement, which can cause the fastener to prematurely disengage from the tool. This limitation can become more and more pronounced with increasing distance between the human operator and the fastener installation hole. Also, the fingers (4) may interfere with the structural member (8) when it is desired to remove the tool from the fastener. Specifically, the fingers may spread outward during removal, and their movement can be blocked by the surface (9) on the structural member (8). When this occurs, the fingers can become wedged between the washer (5) and the surface (9), thus requiring further effort to remove the tool. Additionally, it has been found that this tool is not well suited for use when only a fastener will be installed, instead of a fastener and a washer.
Fastener gripping apparatus is provided which can be used in connection with a shaft having a driver portion. The apparatus can grip a fastener, position the fastener at a remote location, and move the fastener from an uninstalled condition to an installed condition in a structural member. When the fastener is moved towards the installed condition, the apparatus detaches from the fastener for removal from the installation site. The apparatus can be used to install a fastener with or without associated hardware, such as washers. Moreover, the apparatus can also be used to move a fastener, with or without washers, from the installed condition to the uninstalled condition.
The apparatus can include a chassis with a first end, a second end, and a passage extending between the ends. The shaft can be positioned in the passage with the driver portion extending from the second end. A retainer that is moveable between a closed position and an open position can be connected to the chassis, and includes a retaining end positioned adjacent the second end. A contact surface or means on the retaining end is positioned to hold the fastener against the driver portion when the retainer is in the closed position. A cam surface or means is positioned on the retaining end to engage the structural member to move the retainer from the closed position to the open position when the fastener is moved from the uninstalled condition to the installed condition.
The retainer can include a pivot end pivotally connected to the chassis, so that the retainer pivots about the pivot end when moving between the open position and the closed position. A biasing means normally biases the retainer towards the closed position. The biasing means can be a spring extending between the chassis and the retainer.
The retainer can include a slideable member for adjusting a position of the contact surface relative to the driver portion and substantially in the directions of a longitudinal axis of the passage. The slideable member may be the retaining end.